The seat post of a bicycle supports the seat of the bicycle connecting it to the bicycle frame. Known seat posts comprise a round, square or aerodynamic cross section with a continuous tube wall and a bracket at the top end to which the bicycle saddle or seat can be attached. The seat post normally is inserted in the seat tube of the bicycle and held in place by a clamp at the top of the seat tube.
Different materials have been used to save costs, increase strength and reliability and increase stiffness. Different shapes have been used and the aerodynamic shape has become quite common. The aerodynamic shape helps to reduce the overall drag of a bicycle frame particularly as it is normally used in conjunction with an aerodynamic seat tube. These seat tubes are however typically quite rigid, and as a result transmit shock and vibration directly to the seat and rider.
Many different configurations have been introduced to reduce vibration and shock through the seat tube, including springs, shock absorbing cylinders, mechanical levers and elastomer sleeves between the seat post and seat tube. These configurations typically add weight to the bicycle and can involve complicated mechanisms which are expensive to make.
In view of the foregoing, there remains a need for improvements in the art of seat posts for use with bicycles and like wheeled vehicles.